Non-contact power transmission device and design method thereof

Abstract

A non-contact power transmission device is disclosed. The resonant system includes a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil is connected to the load. When the relationship between an input impedance of the resonant system and a frequency of an AC voltage of the AC power source is shown in a graph, the frequency of the AC voltage of the AC power source is set between a first frequency at which the input impedance has a local maximum value, and a second frequency that is greater than the first frequency and at which the input impedance has a local minimum value.

1 . A non-contact power transmission device comprising an AC power source, a resonant system, and a load,
 the resonant system including a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil connected to the load,   the non-contact power transmission device being characterized in that, when the relationship between an input impedance of the resonant system and a frequency of an AC voltage of the AC power source is plotted on a graph, the frequency of the AC voltage of the AC power source is set between a first frequency, at which the input impedance has a local maximum value, and a second frequency, which is greater than the first frequency and at which the input impedance has a local minimum value.   
     
     
         2 . The non-contact power transmission device according to  claim 1 , wherein the frequency of the AC voltage of the AC power source is set to a frequency between the first frequency and the second frequency, and at which the input impedance and an impedance of the primary coil are equal to each other. 
     
     
         3 . The non-contact power transmission device according to  claim 1 , wherein the primary coil, the primary resonance coil, the secondary resonance coil, and the secondary coil have the same diameter. 
     
     
         4 . A non-contact power transmission device comprising an AC power source, a resonant system, and a load,
 the resonant system comprising a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil connected to the load,   the non-contact power transmission device being characterized in that a frequency of an AC voltage of the AC power source is set within an input impedance decreasing range, which is a frequency range in which an input impedance of the resonant system is decreased as the frequency of the AC voltage is increased.   
     
     
         5 . The non-contact power transmission device according to  claim 4 , wherein the frequency of the AC voltage of the AC power source is set to a frequency that is in the input impedance decreasing range and at which the input impedance and an impedance of the primary coil are equal to each other. 
     
     
         6 . The non-contact power transmission device according to  claim 4 , wherein the primary coil, the primary resonance coil, the secondary resonance coil, and the secondary coil have the same diameter. 
     
     
         7 . A method for designing a non-contact power transmission device comprising an AC power source, a resonant system, and a load,
 the resonant system including a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil connected to the load,   the design method being characterized in that, when the relationship between an input impedance of the resonant system and a frequency of an AC voltage of the AC power source is plotted on a graph, the frequency of the AC voltage of the AC power source is set between a first frequency, at which the input impedance has a local maximum value, and a second frequency, which is greater than the first frequency and at which the input impedance has a local minimum value.   
     
     
         8 . The method according to  claim 7 , wherein the frequency of the AC voltage of the AC power source is set to a frequency between the first frequency and the second frequency, and at which the input impedance and an impedance of the primary coil are equal to each other. 
     
     
         9 . A method for designing a non-contact power transmission device comprising an AC power source, a resonant system, and a load,
 the resonant system including a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil connected to the load,   the design method being characterized in that a frequency of an AC voltage of the AC power source is set within an input impedance decreasing range, which is a frequency range in which an input impedance of the resonant system is decreased as the frequency of the AC voltage is increased.   
     
     
         10 . The method according to  claim 9 , wherein the frequency of the AC voltage of the AC power source is set to a frequency that is in the input impedance decreasing range and at which the input impedance and an impedance of the primary coil are equal to each other.